Guida
Kushiro Shitsugen is one of the largest wetland areas in Japan. The Onne-nai Wooden Boardwalk is a scenic 4km path located near the Onne-nai Visitor Center at the western end of the wetland. It was constructed using the remains of the old Tsurui Village railway line. This route provides an exceptional environment for observing the various plants and bird species that inhabit the wetland. As part of the Kushiro Shitsugen National Park, the area is strictly regulated to protect its delicate ecosystem.
The formation of the Kushiro wetlands is closely linked to climate changes from thousands of years ago. Approximately 6,000 years ago, when sea levels were 2 to 3 meters higher than they are today, this area formed a large, shallow bay. As temperatures dropped, the sea level receded, turning the area into a marshland with poor drainage. Over time, the accumulation of reeds and sedges led to peat formation, resulting in the wetland structure seen today about 3,000 years ago.
Historically, records show that in 1858, Musashiro Matsura traveled down the Kushiro River and traversed the wetlands. In 1935, the area was designated as a national monument for the breeding grounds of the Red-crowned Cranes. While some land was converted for agriculture or pasture in the post-war era, the area was registered under the Ramsar Convention in 1980 and designated as Kushiro Shitsugen National Park in 1987. Today, maintaining biodiversity and nature conservation remains a top priority.
Visitors can enjoy breathtaking views of the wetlands through various observation decks and walkways. Near the Onne-nai Visitor Center at the western end, the boardwalk offers an intimate way to observe local flora and fauna. For a wider perspective, the Hosooka Observatory at the eastern end provides a panoramic view of the winding Kushiro River. Additionally, you can experience the landscape from a train window via the JR Senmo Main Line. The landscape features iconic geological formations such as Miyajima Cape and Kirakotan Cape.
The landscape of Kushiro Shitsugen changes beautifully with the seasons. From March to October, you can witness active plant growth and bird activity. Summer is particularly ideal for observing wildlife and lush vegetation. However, during the winter months, access to the wooden boardwalk may be restricted or subject to safety-related closures due to heavy snow and harsh weather. It is highly recommended to check the latest weather reports and access restrictions before your visit.
There are many ways to connect with nature in this area. Beyond walking the Onne-nai Boardwalk, you can experience the wetlands from a different angle by taking a canoe tour through the rivers. For a relaxing view, the JR Senmo Main Line runs through the heart of the wetland. Specifically, the 'Kushiro Shitsugen Norokko-go' sightseeing train offers a unique way to enjoy the scenery while seated comfortably on the train.
To the east of the wetland, you will find the Hosooka Observatory, the Visitor's Lounge, and JR Kushiro-shitsugen Station. Along Route 1060, the Cottaro Observatory offers a great view of the Kushiro River's flow and the eastern side of the wetland. To the west, the Onne-nai Visitor Center and the Kushiro City Wetland Observatory serve as key hubs for exploring the western end of the area. Combining these different locations and observatories allows for a comprehensive experience of the wetland's diverse facets.
Since you will be walking on wooden boardwalks and maintained paths, comfortable walking shoes are essential. Because weather conditions can change rapidly, it is highly recommended to bring rain gear and warm clothing. There are no roads for cars within the wetland itself; visitors must strictly stay on the designated paths to protect the plants and prevent falls into marshy areas.